(19)
(11) EP 0 684 106 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
21.08.1996 Bulletin 1996/34

(43) Date of publication A2:
29.11.1995 Bulletin 1995/48

(21) Application number: 95302845.3

(22) Date of filing: 27.04.1995
(51) International Patent Classification (IPC)6: B24B 19/22
(84) Designated Contracting States:
DE FR GB NL

(30) Priority: 23.05.1994 JP 133773/94
24.06.1994 JP 165914/94

(71) Applicant: Sumitomo Electric Industries, Ltd.
Osaka 541 (JP)

(72) Inventors:
  • Tanabe, Keiichiro, c/o Itami Works of
    Itami-shi, Hyogo (JP)
  • Ikegaya, Akihiko, c/o Itami Works of
    Itami-shi, Hyogo (JP)
  • Seki, Yuichiro, c/o Itami Works of
    Itami-shi, Hyogo (JP)
  • Fujimori, Naoji, c/o Itami Works of
    Itami-shi, Hyogo (JP)

(74) Representative: Smith, Norman Ian et al
F.J. CLEVELAND & COMPANY 40-43 Chancery Lane
London WC2A 1JQ
London WC2A 1JQ (GB)

   


(54) Polishing apparatus and method to produce a hard material-coated wafer


(57) A complex wafer (2) having a soft, fragile substrate and a hard-material film coating on the substrate is difficult to polish, because of the hardness of the film, the fragility of the substrate and the inherent distortion. The complex wafer (2) is stuck in a convex-distorted shape to a holder (3). Preferably, a buffer (11) is inserted between the wafer (2) and the bottom of the holder (3). Further, insertion of a convex spacer is effective to reform a inherently flat wafer (2) or a inherently concave-distorted wafer (2) into a convex-distortion on the holder (3). The holder (3) can incline a little to its own shaft (4). The convex-distorted wafer (2) is in contact with a rotary whetstone turn-table (1). Auxiliary shafts (10) push the periphery of the holder (3) for inclining the holder (3). Slight slanting of the holder (3) changes the contact point on the wafer (2). The slanting angle can be adjusted by the allotment of the force between the main shaft (4) and the auxiliary shafts (10). The roughness of the polished surface is less than Rmax50nm and less than Ra20nm.






Search report